Study on dynamic visual acuital specialty medical surgical and non study National Institute of Neurology and Neurosurgery

Abstract

The visual acuity (VA) is the ability to discriminate fine details of an object in the visual field. There are multiple methods to measure the VA, one of the most used is the Snellen test, however it does not evaluate completely visual function, it is necessary to use other tests such as contrast sensitivity test, chromatic vision test, stereopsis and dynamic visual acuity. Previous studies have demonstrated differences in some of these functions such as dynamic visual acuity depending on the subject’s specific activity. Objectives: the aim of this study was to assess the visual function of surgical and not surgical residents in the National Institute of Neurology and Neurosurgery “Dr. Manuel Velasco Suárez” (INNN) and secondarily to make a comparison between the two groups to determine if there was a significant difference. Methods: we conducted a longitudinal prospective open study which included residents of surgical and non-surgical specialties at INNN, all them were conducted of vision Snellen test, color Ishihara’s vision test, Stereopsis, dynamic visual acuity and contrast sensitivity. Results: all of the cases had best visual acuity equal to or better than 20/20, in all cases the chromatic sensitivity was 8/8. Contrast sensitivity and Stereopsis were appropriate in 100% of cases. We found a statistically significant difference in contrast sensitivity test between the surgical and the non-surgical groups, being better in the first showing a value of 3.2 (p = 0.011). Similarly there was a shorter response time in the dynamic visual acuity test in surgical residents at high and medium contrasts (1.00 and 1.50 in the Pelli-Robson’s algorithm) was 0.1-0.2 seconds faster response in this group (p = 0.01). Best response in women to stimulation in low contrast (2.00) in the non-surgical group was observed (p = 0.026). Stereoacuity was higher in the surgical group, with a value of 20 seconds of arc vs 25 seconds of arc in the nonsurgical group (p = 0.007). There were no differences on Stereopsis, contrast sensitivity and time of response related to the age.